Desk fans allow individual thermal adjustment in shared spaces which increases occupants' thermal satisfaction. When associated with the increase of room conditioning system setpoint temperature, they can also reduce energy use. In comparison to other Personal Comfort Systems (PCS), low-power desk fans can be very efficient for cooling. Nevertheless, previous studies identify some barriers to their implementation and show no clear guidelines on how to overcome them. Therefore, this study presents the results of a field implementation of desk fans in an open office in Brazil. The intervention consisted of providing one desk fan for each occupant and progressively increasing the setpoint temperature. Indoor thermal conditions were recorded simultaneously with occupants' thermal perception using sensors and surveys. Results show fans increased thermal satisfaction by 20 %. And, when fans were available, the preferred indoor air temperature increased by 1 °C. However, many constraints affect the results. Based on this experience, we propose guidelines for future implementation. We emphasize the need to understand the HVAC system, engage building operators, and apply gradual temperature modification. As occupants’ expectations had a great impact on the potential temperature extension, we suggest a way to limit temperature extension in future implementations.

Natural ventilation is a default conditioning strategy in the Brazilian residential sector, while fans and air conditioners are complementary strategies. However, climate change and the increasing air conditioning penetration in this sector threaten the prevalence of natural ventilation and the potential wind-driven (breeze) performance on households’ thermal comfort. A questionnaire survey launched across Brazil assessed multiple aspects of natural ventilation at home: perceptions, usage patterns and motivations behind its use or avoidance. Data analysis methods were multinomial logistic regression and contingency tables of categorical data. The findings indicated that households’ preference for a conditioning strategy related to income and energy-saving concerns (economic aspects). The frequency of use of natural ventilation showed a decreasing trend towards the higher income level and preference for air conditioning. In contrast, the frequency of use of natural ventilation tended to increase as households considered it more positively. Moreover, participants who preferred to use natural ventilation at home expressed less dissatisfaction with the oscillation and unpredictability of the breeze from natural ventilation. The survey outcomes highlight the benefits of a favourable scenario for natural ventilation at home, potentially impacting households’ preferences and routines.

User satisfaction surveys play a crucial role in assessing Indoor Environmental Quality (IEQ). Yet, existing databases predominantly reflect data from developed countries, limiting applicability to culturally and climatically diverse regions. This study emphasizes the relevance of evaluating IEQ satisfaction in office buildings by proposing a standardized, open-access occupant survey system (OSS) for global application. User satisfaction surveys were selected as references from literature for screening and content analysis. The proposed OSS features a two-part survey that triggers detailed questions based on reported IEQ domain-related discomfort frequency. Evaluation process to ensure survey validity incorporated feedback from experts and laypersons. Additionally, a broader application was carried out with 115 office employees. Results identified prevalent issues such as acoustic and thermal discomfort, varying between open-plan and private office layouts. Participants’ responses also showed a significant link between IEQ satisfaction and time spent at the workstation. Overall, the OSS demonstrates its potential as a cost-effective instrument to provide a comprehensive IEQ diagnostic based on occupants’ perceptions. Future iterations should integrate concurrent building measurements to enhance evaluation precision and broaden the applicability of the survey tool across diverse environmental and cultural contexts.

Improvements in the thermal and energy performance of buildings usually involves techniques with high computational costs, such as multi-objective optimization and parametric simulation. However, sometimes, achieving the optimal case is not desirable, though only the refinement of thermal performance. Hence, methods that enable this analysis are helpful for designers and researchers. Then, this study proposed a framework based on the Heat Exchange Index to assist thermal performance analysis of buildings. The framework consists of two phases and begins by exploring air and surface heat balance derived from the base case building simulation. This analysis is based on the Heat Exchange Index, an index developed in this work, and its result indicates the impact of each heat exchange on the thermal performance. The next phase is the improvement, where strategies are defined and implemented, and the thermal performance of the improved case is evaluated against the base case. A single-family house was modeled using EnergyPlus to demonstrate the framework application. Results showed that the Heat Exchange Index could be used to enhance the thermal performance of buildings since the strategies adopted in the base case increased its thermal autonomy and decreased thermal load.